From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nathan Cutler Subject: Re: which osds get used for ec pool reads? Date: Thu, 14 May 2015 21:07:56 +0200 Message-ID: <5554F28C.8040706@suse.cz> References: <1146045701.21089476.1431622348438.JavaMail.zimbra@redhat.com> <755F6B91B3BE364F9BCA11EA3F9E0C6F2CD8C782@SACMBXIP01.sdcorp.global.sandisk.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: Received: from cantor2.suse.de ([195.135.220.15]:54672 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030258AbbENTH7 (ORCPT ); Thu, 14 May 2015 15:07:59 -0400 Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 01213ABB3 for ; Thu, 14 May 2015 19:07:58 +0000 (UTC) In-Reply-To: Sender: ceph-devel-owner@vger.kernel.org List-ID: To: ceph-devel On 05/14/2015 08:33 PM, Gregory Farnum wrote: > If you read every block, you increase the amount of data accessed but > can avoid the long tail latencies. There are a bunch of research > papers about these tradeoffs and the surprising latency improvements > you can get on the aggregate read, and Yahoo! talked about this in > their blog post on their use of Ceph. :) Here's the link, might save some googling: http://yahooeng.tumblr.com/post/116391291701/yahoo-cloud-object-store-object-storage-at